澧水水沙变化特征及成因分析

Characteristics of Water and Sediment Discharge in Lishui River and Factor Analysis

以澧水控制站石门站和津市站多年长系列水文数据为基础,运用M-K趋势检验、小波分析和双累积曲线法等,分析了澧水水沙变化特性及其成因.结果表明：1960～2007年澧水石门站和津市站的年径流量呈波动状态,无显著上升下降趋势,在9a尺度上有较显著的丰枯周期;月径流量表现为1月、2月有明显增加的趋势,发生突变的时间为1998年,4月、10月有所减少,突变时间为2004年,其他月份无明显变化;年输沙量总体呈波动下降趋势,突变时间为1998年.进一步分析表明,径流量主要受降水量的调节,人为活动特别是水库建设是年内径流分配变化的主要原因,而输沙量则受到径流量、大型水库和水土保持工程的综合影响.

Based on hydrological data of the Shimen and Jinshi stations from 1960 to 2007, the changing characteristics and causes of the runoff and sediment discharge in the Lishui River were investigated, using Mann-Kendall trend test,wavelet analysis and double mass analyses. The results show that the annual runoff changes of Shimen and Jinshi stations from 1960 to 2007 are obvious, but there is a significant wet and dry period alternation cycle in 9 year scale. The monthly runoff increases significantly in January and February with the abrupt point in 1998, while it decreases in April and October with the abrupt point in 2004. The annual sediment discharge has a downward trend and the abrupt point is 1998. The runoff in Lishui River was mainly controlled by the rainfall. However, the allocation of the annual runoff is mainly caused by the human disturbances, especially the construction of large reservoirs. The decrease of sediment discharge is influenced by the complex impacts of runoff, the construction of large reservoirs and soil and water conservation.